Nifuroxazide induces the apoptosis of human non­small cell lung cancer cells through the endoplasmic reticulum stress PERK signaling pathway.

The aim of the present study was to investigate the molecular mechanism of nifuroxazide (NFZ) in the induction of apoptosis of NCI-H1299 human non-small cell lung cancer (NSCLC) cells through the reactive oxygen species (ROS)/Ca2+/protein kinase R-like ER kinase (PERK)-activating transcription factor 4 (ATF4)-DNA damage inducible transcript 3 (CHOP) signaling pathway. Morphological changes of cells were observed by microscopy, and the apoptosis and intracellular ROS levels of cells were observed by inverted fluorescence microscopy. Cell viability after the addition of the PERK inhibitor, GSK2606414, were detected by Cell Counting Kit-8 assay. Annexin V-FITC was used to detect cell apoptosis, Brite 670 was used to detect intracellular ROS and Fura Red AM was used to detect Ca2+ content. Western blotting was used to detect PERK, phosphorylated (P)-PERK, ATF4, CHOP, P-Janus kinase 2 and P-signal transducer and activator of transcription 3 expression levels. Compared with the dimethyl sulfoxide control group, NFZ inhibited the survival activity in the H1299 NSCLC cell line, in a time- and dose-dependent manner. However, GSK2606414 inhibited the NFZ-induced apoptosis of H1299 cells. GSK2606414 also inhibited the increase in ROS and Ca2+ in H1299 cells induced by NFZ. Western blotting results demonstrated that NFZ significantly increased the expression levels of P-PERK, ATF4 and CHOP, whereas GSK2606414 significantly reduced the NFZ-induced increase in these protein expression levels. In conclusion, NFZ may induce the apoptosis of H1299 NSCLC cells through the ROS/Ca2+/PERK-ATF4-CHOP signaling pathway.

Neuroprotective effects of neural stem cells pretreated with neuregulin1ß on PC12 cells exposed to oxygen-glucose deprivation/reoxygenation.

Studies on ischemia/reperfusion (I/R) injury suggest that exogenous neural stem cells (NSCs) are ideal candidates for stem cell therapy reperfusion injury. However, NSCs are difficult to obtain owing to ethical limitations. In addition, the survival, differentiation, and proliferation rates of transplanted exogenous NSCs are low, which limit their clinical application. Our previous study showed that neuregulin1ß (NRG1ß) alleviated cerebral I/R injury in rats. In this study, we aimed to induce human umbilical cord mesenchymal stem cells into NSCs and investigate the improvement effect and mechanism of NSCs pretreated with 10 nM NRG1ß on PC12 cells injured by oxygen-glucose deprivation/reoxygenation (OGD/R). Our results found that 5 and 10 nM NRG1ß promoted the generation and proliferation of NSCs. Co-culture of NSCs and PC12 cells under condition of OGD/R showed that pretreatment of NSCs with NRG1ß improved the level of reactive oxygen species, malondialdehyde, glutathione, superoxide dismutase, nicotinamide adenine dinucleotide phosphate, and nuclear factor erythroid 2-related factor 2 (Nrf2) and mitochondrial damage in injured PC12 cells; these indexes are related to ferroptosis. Research has reported that p53 and solute carrier family 7 member 11 (SLC7A11) play vital roles in ferroptosis caused by cerebral I/R injury. Our data show that the expression of p53 was increased and the level of glutathione peroxidase 4 (GPX4) was decreased after RNA interference-mediated knockdown of SLC7A11 in PC12 cells, but this change was alleviated after co-culturing NSCs with damaged PC12 cells. These findings suggest that NSCs pretreated with NRG1ß exhibited neuroprotective effects on PC12 cells subjected to OGD/R through influencing the level of ferroptosis regulated by p53/SLC7A11/GPX4 pathway.

Transplantation of Human Umbilical Cord Mesenchymal Stem Cells-Derived Neural Stem Cells Pretreated with Neuregulin1ß Ameliorate Cerebral Ischemic Reperfusion Injury in Rats.

Ischemic stroke is a common cerebrovascular disease and recovering blood flow as early as possible is essential to reduce ischemic damage and maintain neuronal viability, but the reperfusion process usually causes additional damage to the brain tissue in the ischemic area, namely ischemia reperfusion injury. The accumulated studies have revealed that transplantation of exogenous neural stem cells (NSCs) is an ideal choice for the treatment of ischemia reperfusion injury. At present, the source and efficacy of exogenous NSCs after transplantation is still one of the key issues that need to be resolved. In this study, human umbilical cord mesenchymal stem cells (hUC-MSCs) were obtained and induced into NSCs byadding growth factor and neuregulin1ß (NRG1ß) was introduced during the differentiation process of NSCs. Then, the rat middle cerebral artery occlusion/reperfusion (MCAO/R) models were established, and the therapeutic effects were evaluated among groups treated by NRG1ß, NSCs and NSCs pretreated with 10 nM NRG1ß (NSCs-10 nM NRG1ß) achieved through intra-arterial injection. Our data show that the NSCs-10 nM NRG1ß group significantly improves neurobehavioral function and infarct volume after MCAO/R, as well as cerebral cortical neuron injury, ferroptosis-related indexes and mitochondrial injury. Additionally, NSCs-10 nM NRG1ß intervention may function through regulating the p53/GPX4/SLC7A11 pathway, and reducing the level of ferroptosis in cells, further enhance the neuroprotective effect on injured cells.

Evodiamine induces ROS-Dependent cytotoxicity in human gastric cancer cells via TRPV1/Ca2+ pathway.

Evodiamine (EVO), a key active ingredient of the fruit of Evodiae fructus, is provided with antitumor effects (mainly cytotoxic effect) including proliferation inhibition, cell cycle arrest, apoptosis, and metastasis inhibition. Our study aims to explain the underlying role of TRPV1/Ca2+ in EVO-induced cytotoxicity in human gastric cancer cells. Human gastric cancer line BGC-823 was used to study EVO-induced cytotoxicity. Cell viability was examined using CCK-8 assay. Apoptosis was examined using Annexin V-FITC/PI staining assay. Intracellular ROS ([ROS]i) levels were examined using DCFH-DA assay. Mitochondrial morphology was examined using Mitotracker Green staining. Mitochondrial membrane potential (Δψm) were examined using JC-1 assay. Intracellular Ca2+ levels ([Ca2+]i) were examined using Fluo-4 AM assay. Mitochondrial ROS ([ROS]m)levels were examined using Mitotracker Green/MitoSOX Red staining. Mitochondrial Ca2+ ([Ca2+]m)levels were examined using Mitotracker Green/Rhod-2 Red staining. The protein levels was detected by Western blot. EVO exposure causes significant ROS generation and apoptotic cell death. Pretreatment of EUK134 significantly ameliorated EVO-induced apoptotic cell death. Furthermore, EVO exposure induced [ROS]i generation and mitochondrial dysfunction, including [ROS]m generation and Δψm dissipation, which can be significantly attenuated by pre-incubation of rotenone indicating that [ROS]m is the main source of EVO-induced intracellular ROS generation. Importantly, EVO-induced cytotoxicity was significantly ameliorated by intracellular Ca2+ chelation, confirming that EVO induces cell death through Ca2+ overload. Pharmacological and genetic inhibition of TRPV1 could significantly attenuate Ca2+ influx, ROS generation and apoptotic cell death induced by EVO exposure, while exogenous TRPV1 overexpression could augment the EVO-induced cytotoxicity. Moreover, genetic inhibition of mitochondrial calcium uniporter (MCU) attenuated EVO-induced cell death and mitochondrial dysfunction. EVO exposure induced endoplasmic reticulum (ER) stress demonstrated by the activation of PERK/CHOP in cells exposed to EVO, and PERK/CHOP activation was depleted by EUK134 pre-treatment. Our results support the concept that EVO induces ROS-dependent cytotoxicity via TRPV1/Ca2+ Pathway.

Effect of evodiamine on cell death pathways in human gastric cancer cells.

Evodiamine (EVO) exerts anti-cancer effect in a majority of cancer cells. BGC-823 and SGC-7901 cells were used to study EVO-induced cytotoxicity in human gastric cancer cell. Our results demonstrated that EVO exposure elicited cell vialibility decrease and G2/M arrest caused by induction of cdc2/cyclin B1 complex activation. EVO also induced caspase-dependent apoptosis and necroptosis caused by induction of actication of RIP, RIP3 and MLKL. Moreover, increase of reactive oxygen species (ROS) levels and cytotoxicity induced by EVO were significantly attenuated by co-treatment with a ROS scavenger, EUK134. In conclusion, EVO induced ROS-dependent cytotoxicity, which may involve apoptosis and necroptosis, in human gastric cancer cells.

Cerebroprotein Hydrolysate-I Inhibits Hippocampal Neuronal Apoptosis by Activating PI3K/Akt Signaling Pathway in Vascular Dementia Mice.

INTRODUCTION: Vascular dementia (VaD), one of the brain injuries, is difficult to be cured, so it is important to take active neuroprotective treatment after its occurrence. Many studies have shown that apoptosis serves an important role in VaD occurrence; therefore, inhibition of apoptosis may contribute to the recovery of neurological function after VaD occurrence. Cerebroprotein hydrolysate-I (CH-I), a neuropeptide preparation which consists of several amino acids and small molecular peptides as the main active constituent, is extracted using a method similar to cerebrolysin (CBL) which has neuroprotective and neurotrophic effects. METHODS: In the present study, a VaD model which was constructed using bilateral common carotid artery occlusion (BCCAO) in Kunming mice was applied to examine the neuroprotective effects of CH-I. RESULTS: The results show that CH-I treatment could attenuate the decrease of learning and memory ability, cell apoptosis in the hippocampal CA1 region and inhibit the activation of caspase-3 and caspase-9 in VaD mice. Furthermore, CH-I treatment could also upregulate Bcl-2 protein levels and activate PI3K and Akt. DISCUSSION: We speculate that CH-I may induce a neuroprotective effect activating PI3K/Akt signaling pathway in VaD mice.

Evodiamine induces reactive oxygen species-dependent apoptosis and necroptosis in human melanoma A-375 cells.

Melanoma is a common solid malignant tumor with a high frequency of metastasis and relapse. Evodiamine (EVO), a natural small molecule, has recently attracted considerable attention due to its pharmacological action, including its anticancer effects. However, the mechanism of the cytotoxic effect exerted by EVO on tumor cells is not yet fully understood. The present study aimed to evaluate the antitumor effects of evodiamine in human melanoma A-375 cells. The results demonstrated that EVO inhibited cell proliferation and induced cell cycle arrest at the G2/M stage in human melanoma A-375 cells. The results also revealed that EVO exposure induced the activation of caspase-3, caspase-9 and poly (ADP-ribose) polymerase 1, as well as mitochondrial membrane potential dissipation in a time-dependent manner, indicating that EVO induced intrinsic apoptosis in A-375 cells. Furthermore, the results revealed that receptor-interacting serine/threonine kinase (RIP) and RIP3 were sequentially activated, suggesting that necroptosis may also be involved in EVO-induced cell death in A-375 cells. In addition, co-treatment with catalase was demonstrated to significantly attenuate the EVO-induced cell death in A-375 cells, indicating that reactive oxygen species (ROS) may serve an important role in EVO-induced cell death. In conclusion, the results of the present study unveiled a novel mechanism of drug action by EVO in human melanoma cells and suggested its potential value in treating human melanoma by inducing cell death via ROS activation.

Activation of NLRP3 inflammasome in RAW 264.7 cells by polysaccharides extracted from Grateloupia livida (Harv.) Yamada.

Polysaccharides have been proven to be involved in the immune response in both anti-inflammation and pro-inflammation due to their distinct pharmacological properties. Recent studies showed that polysaccharides from Grateloupia livida (Harv.) Yamada possessed several biological activities, including anti-oxidant, anti-angiogenic, anti-cancer and antiviral. Our previous work has elucidated the structural features of the polysaccharides (named WGW) by combining ESI-MS with NMR and infrared (IR) spectroscopic analyses. The polysaccharides were mainly composed of galactose linked with sulfate ester, concluding to be µ-carrageenan and κ-carrageenan. The purpose of this study was to investigate the immunoregulation effects of WGW on macrophage RAW 264.7 cell. The cells were treated with WGW for different times, then Griess reagent was applied to detect the production of NO. The results presented that WGW induced the release of NO in large quantities (ranging from 2 µg/mL to 256 µg/mL) and improved the phagocytosis of macrophage RAW264.7 cells. Furthermore, WGW have a predominant role in the improvement of proinflammatory mediators, such TNF-α, IL-1ß, iNOS, MMP-9 and COX2. Moreover, WGW activated NLRP3 inflammasome, in which MAPK/NF-κB signaling pathway played an important role. These results indicated WGW might be a potential immuno-stimulation drug to promote inflammation.

Selection and Characterization of a Novel DNA Aptamer, Apt-07S Specific to Hepatocellular Carcinoma Cells.

BACKGROUND: The efficacy of traditional therapeutic methods for liver cancer is unsatisfying because of the poor targeting, and inefficient drug delivery system. A recent study has proven that aptamers, developed through cell-SELEX, could specifically recognize cancer cells and show great potential in the development of a delivery system for anticancer drugs. PURPOSE: To develop a hepatocellular carcinoma specific aptamer using two kinds of hepatocellular carcinoma cell lines, HepG2 and SMMC-7721, as double targets and a normal hepatocyte, L02, as a negative control cell. METHODS: Hepatocellular carcinoma specific aptamer was developed via cell-SELEX. The enrichment of the library was monitored by flow cytometric analysis. The specificity, affinity, and distribution of the candidate aptamer were explored. Further study was carried to assess its potential in drug delivery. RESULTS: The library was enriched after 14 rounds of screening. Candidate aptamer Apt-07S can recognize four kinds of hepatocellular carcinoma cells and show little cell-binding ability to normal cells and four cell lines of different cancer types, revealing a high specificity of Apt-07S. Confocal imaging showed that Apt-07S distributed both on the surface and in the cytoplasm of the two target cells. Moreover, an anti-sense nucleotide to gene Plk1 (ASO-Plk1) was connected at the 3' end of Apt-07S to form an integrated molecule (Apt-07S-ASO-Plk1); the functional analysis indicated that the structure of Apt-07S may help ASO-Plk1 enter the cancer cells. CONCLUSION: The study indicates that Apt-07S can specifically target HCC and may have potential in the delivery of anticancer drugs.

The suppressive effect of co-inhibiting PD-1 and CTLA-4 expression on H22 hepatomas in mice.

OBJECTIVE: We investigated the suppressive effect of siRNA-mediated co-inhibition of PD-1 and CTLA-4 expression on H22 hepatomas in mice. METHODS: Murine H22 cells were cultured in vivo in ICR mice. An allograft tumor model was also established in another ICR mouse group. The tumor-bearing mice were randomly divided into four groups: control, single PD-1 siRNA, single CTLA-4 siRNA, and double PD-1 + CTLA-4 siRNAs. The survival time and physiological condition of the mice were observed after the injection of the siRNAs and placebo. The volume and weight of the solid tumor were measured to assess the inhibition of the tumor. To assess the effects of siRNAs on mouse immune function, the protein levels of IFN-γ and IL-10 in the blood and PD-L1 in the tumor and liver were determined using ELISA, and the mRNA levels of IFN-γ, PD-L1, PD-1, CTLA-4, IL-6 and Survivin in the tumor, liver and spleen were determined using quantitative RT-PCR. The ratios of Bax and Bcl-2 protein were determined via western blot to analyze the effect of siRNAs on tumor cell apoptosis. RESULTS: The anti-tumor effect appeared in all groups with siRNA-mediated inhibition. The tumor growth suppression was stronger in the group with double inhibition. The weight and volume of the tumors were significantly lower and the survival rate improved in the three siRNA groups. IFN-γ levels increased but IL-10 levels decreased in the blood of the siRNA group mice compared with the results for the control group. In the tumor and spleen tissue, the IFN-γ levels significantly increased, but in the liver tissue they significantly decreased in the three siRNA groups. The results of quantitative RT-PCR showed that the mRNAs for PD-1 and CTLA-4 were downregulated in spleen tissue in the three siRNA groups, while the PD-L1 mRNA and protein levels increased significantly in the tumor, but decreased in the liver. Survivin and IL-6 mRNA levels decreased in the tumor. Western blot results showed that ratio of Bax and Bcl-2 had significantly increased. These results indicated that downregulating PD-1 and CTLA-4 could increase the body's immune response and promote apoptosis of tumor cells. CONCLUSION: Co-inhibiting the expressions of PD-1 and CTLA-4 can effectively suppress the growth of H22 hepatoma and promote the apoptosis of tumor cells in mice. Blocking PD-1 and CTLA-4 can improve the vitality of T cells, and improve the immune environment and response.

Anti-inflammatory effect of low molecular weight fucoidan from Saccharina japonica on atherosclerosis in apoE-knockout mice.

Atherosclerosis (AS) is the key cause of many cardiovascular and cerebrovascular diseases. The inflammatory response and lipid metabolism disorders contribute to the development and progression of AS. This work aims to study the anti-inflammatory effect and mechanism of low molecular weight fucoidan (LMWF) obtained from Saccharina japonica on atherosclerosis in apoE-knockout mice. The experimental results showed that LMWF statistically decreased the levels of triglyceride (TRIG) and oxidative low-density lipoproteins (ox-LDL) and stabilized established atherosclerotic lesions. LMWF ameliorated the inflammatory response by down regulating IL-6 and by up regulating IL-10 transcriptional levels, and LMWF returned p-JNK and cyclin D1 to normal levels. Moreover, LMWF increased the mRNA level of CD11b in the aorta and suppressed the expression of CD11b in the intimal layer of the aorta. Therefore, LMWF prevented macrophages from developing into foam cells and prevented SMCs from migrating into the intimal layer of the aorta, which inhibited the formation of atherosclerotic plaques; and ameliorated the occurrence and development of AS.

Effects of n-3PUFAs on autophagy and inflammation of hypothalamus and body weight in mice.

OBJECTIVE: Fat-1 transgenic mice were used as a model to study the effect of endogenous n-3 polyunsaturated fatty acids (n-3PUFAs) on the body weight, inflammatory factors and autophagy proteins in hypothalamus to explore the mechanism of n-3PUFAs inhibiting obesity. METHOD: The mice were divided into two groups after genotype identification: fat-1 transgenic mice and wild-type mice. The body weight and body length of mice were measured at 14th week, and calculated the Lee 's index. The autophagosome in arcuate nucleus neurons was observed through electron microscopy; the expression of autophagy protein P62, LC3 and ATG7 in hypothalamus were detected and analyzed quantitatively by immunofluorescence and Western blot techniques. The mRNAs of inflammatory factor TNF-α, IL-6, IL-1ß, NF-kB, chemokine MCP-1, CCL5, CXCL12, CX3CL1, microglia markers TMEM119, GFAP were detected by real-time fluorescence quantitative PCR. RESULT: The Lee's index of fat-1 transgenic mice was lower than that of wild-type mice(P < 0.05). The autophagosome of the arcuate nucleus in fat-1 transgenic mice were more than those in wild-type mice, and the expression of autophagy-related protein P62 was significantly decreased (P < 0.05) in hypothalamus of fat-1 transgenic mice, while the expression of autophagy related protein ATG7 was significantly up-regulated (P < 0.05), and the ratio of LC3 II/I was significantly increased (P < 0.05), The results of qPCR showed that the mRNAs of TNF-α, IL-6, IL-1ß, NF-kB, MCP-1, CCL5, CXCL12, and GFAP was significantly down regulated (P < 0.05), but CX3CL1 was significantly up-regulated (P < 0.05) in hypothalamus of fat-1 transgenic mice. CONCLUSION: Fat-1 gene or n-3 PUFAs possesses the function of reducing body weight, which involves the enhancement of autophagy and reduction of inflammatory factor in hypothalamus.

Picroside II Exerts a Neuroprotective Effect by Inhibiting mPTP Permeability and EndoG Release after Cerebral Ischemia/Reperfusion Injury in Rats.

Mitochondrial membrane permeability is closely related to cerebral ischemia/reperfusion (I/R) injury. This paper explored the neuroprotective effect of picroside II (Picr), which inhibits the permeability of mitochondrial permeability transition pore (mPTP) and endonuclease G (EndoG) release from mitochondria into cytoplasm after cerebral I/R in rats. After 2 h of cerebral ischemia and 24 h of reperfusion in rats with different intervention measures, the neurobehavioral function, infarction volume, and reactive oxygen species (ROS) content in brain tissues were observed by modified neurological severity scale (mNSS), triphenyl tetrazolium chloride (TTC) staining, and enzyme-linked immunosorbent assay, respectively. The permeability of mPTP was assayed using spectrophotometry. The morphology and apoptotic cells of brain tissues were observed by hematoxylin-eosin staining and terminal deoxynucleotidyl transferase dUTP nick end labeling assay, respectively. The expressions of EndoG and voltage-dependent anion channel 1 (VDAC1) were determined by immunohistochemical assay and western blot. The Picr group exhibited clear decreases in mNSS scores, ROS content, number of apoptotic cells, mPTP permeability and expression of VDAC1, and EndoG in cytoplasm and nuclei, and the morphology of brain tissue was improved as compared with the model group (P < 0.05). Picr could attenuate cerebral I/R injury by downregulating the expression of VDAC1 and decreasing the permeability of mPTP, thereby inhibiting EndoG release from mitochondria into cytoplasm.

Neuregulin1ß Effects on Brain Tissue via ERK5-Dependent MAPK Pathway in a Rat Model of Cerebral Ischemia-Reperfusion Injury.

Neuregulin1ß (NRG1ß), a member of the excitomotor of tyrosine kinase receptor (erbB) family, was recently shown to play a neuroprotective role in cerebral ischemia-reperfusion injury. The present study analyzed the effects and its possible signaling pathway of NRG1ß on brain tissues after cerebral ischemia-reperfusion injury. A focal cerebral ischemic model was established by inserting a monofilament thread to achieve middle cerebral artery occlusion, followed by an NRG1ß injection via the internal carotid artery. NRG1ß injection resulted in significantly improved neurobehavioral activity according to the modified neurological severity score test. Tetrazolium chloridestaining revealed a smaller cerebral infarction volume; hematoxylin-eosin staining and transmission electron microscopy showed significantly alleviated neurodegeneration in the middle cerebral artery occlusion rats. Moreover, expression of phosphorylated MEK5, phosphorylated ERK5, and phosphorylated MEK2C increased after NRG1ß treatment, and the neuroprotective effect of NRG1ß was attenuated by an injection of the MEK5 inhibitor, BIX02189. Results from the present study demonstrate that NRG1ß provides neuroprotection following cerebral ischemia-reperfusion injury via the ERK5-dependent MAPK pathway.

Tumor-selective replication herpes simplex virus-based technology significantly improves clinical detection and prognostication of viable circulating tumor cells.

Detection of circulating tumor cells remains a significant challenge due to their vast physical and biological heterogeneity. We developed a cell-surface-marker-independent technology based on telomerase-specific, replication-selective oncolytic herpes-simplex-virus-1 that targets telomerase-reverse-transcriptase-positive cancer cells and expresses green-fluorescent-protein that identifies viable CTCs from a broad spectrum of malignancies. Our method recovered 75.5-87.2% of tumor cells spiked into healthy donor blood, as validated by different methods, including single cell sequencing. CTCs were detected in 59-100% of 326 blood samples from patients with 6 different solid organ carcinomas and lymphomas. Significantly, CTC-positive rates increased remarkably with tumor progression from N0M0, N+M0 to M1 in each of 5 tested cancers (lung, colon, liver, gastric and pancreatic cancer, and glioma). Among 21 non-small cell lung cancer cases in which CTC values were consecutively monitored, 81% showed treatment-related decreases, which was also found after treatments in the other solid tumors. Moreover, monitoring CTC values provided an efficient treatment response indicator in hematological malignancies. Compared to CellSearch, our method detected significantly higher positive rates in 40 NSCLC in all stages, including N0M0, N+M0 and M1, and was less affected by chemotherapy. This simple, robust and clinically-applicable technology detects viable CTCs from solid and hematopoietic malignancies in early to late stages, and significantly improves clinical detection and treatment prognostication.

A novel oHSV-1 targeting telomerase reverse transcriptase-positive cancer cells via tumor-specific promoters regulating the expression of ICP4.

Virotherapy is a promising strategy for cancer treatment. Using the human telomerase reverse transcriptase promoter, we developed a novel tumor-selective replication oncolytic HSV-1. Here we showed that oHSV1-hTERT virus was cytopathic in telomerase-positive cancer cell lines but not in telomerase-negative cell lines. In intra-venous injection in mice, oHSV1-hTERT was safer than its parental oHSV1-17+. In human blood cell transduction assays, both viruses transduced few blood cells and the transduction rate for oHSV1-hTERT was even less than that for its parental virus. In vivo, oHSV1-hTERT inhibited growth of tumors and prolong survival in telomerase-positive xenograft tumor models. Therefore, we concluded that this virus may be a safe and effective therapeutic agent for cancer treatment, warranting clinical trials in humans.

Ginsenoside Rg1 protects against 6-OHDA-induced toxicity in MES23.5 cells via Akt and ERK signaling pathways.

AIM OF THE STUDY: The present study was designed to investigate the neuroprotective effects of ginsenoside Rg1 against 6-hydroxydopamine (6-OHDA)-induced toxicity in MES23.5 cells and their possible mechanisms. MATERIALS AND METHODS: MES23.5 cells were treated with or without Rg1 for 24h before exposure to 6-OHDA. Cell viability was determined by MTS assay. The gene and protein expressions of Bcl-2 were detected by real time RT-PCR and western blotting. Phosphorylation of Akt and ERK1/2 were examined by western blotting. RESULTS: Pretreatment with ginsenoside Rg1 had obvious neuroprotective effects on cell viability against 6-OHDA-induced toxicity. 6-OHDA decreased the gene and protein expressions of Bcl-2. These effects could be reversed by Rg1 pretreatment. Potential cell signaling candidates involved in this neuroprotective effect were examined. 6-OHDA significantly inhibited the phosphorylation of Akt and increased the phosphorylation of ERK1/2 in MES23.5 cells. Pretreatment with ginsenoside Rg1 could increase the Akt phosphorylation and inhibit the ERK1/2 phosphorylation induced by 6-OHDA. Further study revealed that LY294002, an inhibitor of phosphatidylinositol 3-kinase (PI3-K), attenuated the neuroprotective effect of Rg1 on cell viability against 6-OHDA-induced toxicity. CONCLUSIONS: Taken together, our results strongly suggest that ginsenoside Rg1 has neuroprotective effects against 6-OHDA-induced toxicity in MES23.5 cells. Its mechanism includes the up-regulation of Bcl-2 gene expression, the activation of Akt phoshphorylation as well as the inhibition of ERK1/2 phosphorylation induced by 6-OHDA.